11282016 Site Visit and Conceptual Design Study issue

318 McConnell Dr. Lyons, CO, 80540 1

Site Visit and Conceptual Design Study Danville River Park Danville, Virginia

March 2nd, 2017

Prepared for: Graham Smith

DHM Design

727 West Hargett Street, Suite 101

Raleigh, NC 27603

Prepared by: Scott Shipley, P.E. S2o Design and Engineering 318 McConnell Drive Lyons, CO, 80540


Contents

Introduction: ................................................................................................................................................. 3

Site Information ............................................................................................................................................ 4

Regional Population within the Danville Micropolitan Statistical Area .................................................... 4

Hydrology .................................................................................................................................................. 6

Flooding in Danville ................................................................................................................................... 7

Historic Structures in Danville ................................................................................................................... 9

Threatened and Endangered Species ....................................................................................................... 9

Economic Impacts of the Proposed Whitewater Park ............................................................................ 10

Land Ownership .................................................................................................................................. 11

Conceptual Design .............................................................................................................................. 11

The Bypass Channel ................................................................................................................................ 13

The Canal ................................................................................................................................................. 15

Opinion of Probable Costs .................................................................................................................. 18

Permitting ................................................................................................................................................... 20

Federal and State Permitting .................................................................................................................. 20

City of Danville ........................................................................................................................................ 20

Floodplain Development Permit (City or County) ............................................................................... 20

The Design and Construction Process ......................................................................................................... 21

Design ...................................................................................................................................................... 21

Construction ............................................................................................................................................ 22

Appendix B – Conceptual Designs ............................................................................................................... 27


Introduction:

Danville, VA is investing in its waterfront. A planned Riverfront Park is in its planning stages but will

include both wet and dry play areas, parking, a gathering and stage area, river access points, and,

potentially, a whitewater park. Whitewater Parks are a growing trend in the United States. These parks

function both as community riverside parks and active in‐stream features that provide for rafting,

whitewater kayaking, tubing and other healthy, active, outdoor recreational activities. River sports are

some of the fastest growing sports in America and there is a growing trend among many towns and

cities to create these parks in their own backyards. River parks often achieved their original goal of

attracting paddle sports enthusiasts, and often exceeded these expectations by becoming focal points of

their communities and destinations for outdoor recreation‐based tourism from throughout the region.

Whitewater parks often play host to major events centered on slalom or freestyle competitions or to

community celebrations such as river festivals. Additionally, river parks can have a significant economic

impact on the local community, as visitors spend money at local restaurants, hotels, and retail

establishments. Some cities, like Golden, Colorado; and Reno, Nevada have reported impacts on the

local economy, from tourism generated by the park, on the order of millions of dollars per year.

DHM Design has commissioned a study to investigate the preliminary feasibility of creating a Whitewater

component to be included in the Waterfront Park in Danville, VA. The purpose of this study is to begin

the process of conceptualizing possible design solutions that meet project objectives. This report

summarizes the findings of that study.


Site Information

The proposed site is located along the Dan River Mill in Downtown Danville, VA. A context map, provided

by DHM Design, shows the project site in relation to the City of Danville:

Figure 1. A context map for the project site in central Danville, VA.

The project site is located north of downtown adjacent to the White Mill at the corner of Main Street

and Memorial Drive. The former White Mill, which is privately owned, has potential for redevelopment

and is significant in that there is substantial parking available on the site as well as a former industrial

canal that passes the former mill along its western boundary. There is also a historic dam in the river

located just downstream of the White Mill and adjacent to the project area. A potential project in this

location would have significant impacts not just in the project area, but also to the businesses within this

part of Danville. These impacts would draw people from the local community as well as surrounding

region. It is pertinent to the study to understand the local region in the context of the proposed park.

Regional Population within the Danville Micropolitan Statistical Area

The City of Danville, VA is an economic and cultural hub of south‐central Virginia. The Dan River flows

through Danville, just north of the Downtown District. The City is host to numerous cultural events,


festivals, and museums. A River Park in Danville has the potential to further revitalize the City and make

a positive economic and social impact to the community.

While Danville is a smaller city with a population of 43,055 people, the City is located less than 100 miles

from numerous metropolitan areas, including:

Greensboro, NC (Population 269,666)

Durham, NC (Population 251,893)

Winston‐Salem, NC (Population 241,218)

Raleigh, NC (Population 538,066)

A River Park in Danville will draw upon the paddling and adventure minded populations from these nearby

cities and provide a positive overall economic impact to the City (Census, 2014). Studies have shown the

between 2 to 3% of the population in this region of the country identify themselves as avid paddlers or

rafters. These numbers are significant in the context of the local region. The location of Danville is

displayed below in Figure 2, and the surrounding cities are shown in Figure 3

Figure 2: Location Map for Danville, VA.


Figure 3. There are more than 1 million people that live within 100 miles of Danville, VA.

Hydrology

The hydrology of the project sites has been analyzed to identify target flow rates for the project site that

balances both the magnitude and duration of the recreational experiences sought. Stream gauging data

was obtained from a USGS station just upstream of the proposed site (USGS, 2016). Flood flows in Dan

River are seasonal, with highest flows occurring during spring and with lower flows over the summer. The

timing and magnitude of available flows are key factors in the overall potential of a river park.

Average daily and monthly flows are shown below in Figure 4:

Figure 4. Mean Daily Flows for the Dan River (USGS, 2016).

0

1,000

2,000

3,000

4,000

5,000

6,000

Flow Rate (cfs)

Dan River Daily Mean Flows from 1995 ‐ 2016


Gauge data shows that flows are significant throughout the year with peak flows that follow local rainfall

cycles. Higher flows are present throughout the year and tend to rise and fall dramatically. The average

flows by month are shown below in Figure 4:

Figure 5. Average Monthly Flows on the Dan River (USGS, 2016).

Flows in the Dan average almost 3,000 cfs in the spring and average greater than 1500 cfs throughout the

remainder of the year. These flows are higher, on average, than most whitewater parks in America and

are sufficient to create attractive whitewater within a whitewater park that features sufficient drop.

In general, river parks provide a competition‐level whitewater experience in a natural river channels at

flows approaching 1000 cfs or greater. Though expert level whitewater may only be available in peak

runoff events, recreational opportunities including surfing, spinning, rec paddling, tubing, slalom, skills

training, as well as paddle‐through recreation will still be available seasonally. General floating activities,

such as tubing or inexperienced rafting, typically happen in low slope or low flow portions of the river or

during lower flow seasons of the year.

Flooding in Danville

A Flood Insurance Study on Danville, VA was issued on September 29th, 2010 to describe Flood Insurance

Rate Maps (FIRM) for the City of Danville (Federal Emergency Managment Agency, 2010). Danville’s flood

risk stems primarily from the Dan River, which creates a floodplain that inundates up to Memorial Drive

on the south bank of the river and up to Riverside Drive on the north side of the river. The following

naming conventions are used for flood mapping:

Zone A: Areas subject to inundation by the 1% annual chance flood event generally determined

using approximate methodologies. Because detailed hydraulic analyses have not been performed,

0

500

1,000

1,500

2,000

2,500

3,000

3,500

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Flow Rate (cfs)

Average Monthly Flows


no Base Flood Elevations (BFEs) or flood depths are shown. Mandatory flood insurance purchase

requirements and floodplain management standards apply.

Zone AE: Areas subject to inundation by the 1% annual chance flood event determined by

detailed methods. Within Zone AE there can be a subzone known as the “Active Floodway” or

simply “Floodway”. The floodway is the channel of a stream plus any adjacent floodplain areas

that must be kept free of encroachment so that the 1% annual chance flood can be carried without

substantial increases in flood heights. Mandatory flood insurance purchase requirements and

floodplain management standards apply.

Shaded Zone X: Areas of 0.2% annual chance flood; areas of 1% annual chance flood with average

depths of less than 1 foot or with drainage areas less than 1 square mile; and areas protected by

levees from 1% annual chance flood.

A review of the flood hazard zoning for the proposed site shows that it is included in Zone AE, displayed

below in Figure 6. This map shows that the active floodway is located directly adjacent to the southern

bank meaning that improvements in the river will need to be balanced using a HEC‐RAS model to ensure

no‐rise. Proposed changes to the existing channel geometries will require coordination with FEMA to

either demonstrate no‐rise to the effective Base Flood Elevations (BFE) or to revise FIRMs to reflect

changes in 100 year flooding before and following construction activities (undesired).

Figure 6. FEMA flood map of the proposed project site.


Historic Structures in Danville

The City of Danville has a rich history dating back the 18th century when the town was first settled. Danville

was home to the largest textile mill in the world, known as Dan River Inc. The proposed project sites were

subject to a preliminary review for nearby historic properties listed on the National Register of Historic

Places. The proposed River Park lies within Dan River Inc. Riverside Division Historic District, as well as

adjacent to the Dan River Mill No. 8 (National Park Service, US Department of Interior, 2014)

A complete archeological assessment of proposed sites may be required to determine impacts to the

proposed project sites in order to receive 404 Authorization to begin construction. Though this

assessment typically has little impact on in‐channel river parks, the project owner should be aware of this

potential requirement as it could result in significant delays and/or costs to a project if an impact to a

culturally or historically significant site is found.

Threatened and Endangered Species

Using the Endangered Species U.S. Fish and Wildlife Service database, federally listed endangered species

to consider within the greater project areas are shown in Table 1.

Table 1: Listed species within the vicinity of the project sites within the City of Danville (U.S. Fish and Wildlife Service, 2016).

Within the region, there are four species of concern, with two listed as federally endangered and one as

federally threatened. The proposed project area does not contain any Critical Habitat designations for the

listed species, any National Refuge areas or any National Wetlands areas (U.S. Fish and Wildlife Service,

2015), however this does not yet fulfill the requirements of Section 7 of the Endangered Species Act of

which compliance is mandatory for the project to proceed.

Additional assessments of the sites and impacts to these species may need to be conducted during the

preliminary design/permitting stages of the project, especially as there are several federally endangered

species present in the watershed. Additional consultation with the U.S. Fish and Wildlife Service is

anticipated, once the final project configuration is selected, to ensure that it does not include known

populations or critical habitat for federally listed species and/or additional species of concern within the

project areas. If critical habitats are identified, the project will need to work with Fish and Wildlife to

determine if the project, in design or implementation, can minimize impacts in an acceptable manner.

Some species of bird are protected under the Migratory Birds Protection act and the Bald and Golden

Eagle Protection Act. The project will need to comply with the appropriate regulations for these acts

throughout the duration of the construction.

Group Common Name Scientific Name Status

Clams James spinymussel Pleurobema collina Endangered

Clams Atlantic pigtoe Fusconaia masoni Under Review

Fishes Roanoke logperch Percina rex Endangered

Mammals Northern Long‐EaredMyotis septentriona Threatened


Economic Impacts of the Proposed Whitewater Park

An economic impact study for the proposed project has not been conducted yet. However, studies have

been conducted for several similar facilities in the United States. Many of these river parks, built in similar

towns and settings throughout the United States, have become significant tourist attractions. These parks

bring enthusiasts and spectators alike to their respective communities and create measurable economic

impacts through increased property values, direct spending at the site, and tourism dollars spent at local

restaurants, hotels, and businesses. A river park like the ones proposed in Danville could attract tourists

and generate total economic impacts on the order of hundreds of thousands of dollars per year. In‐

stream river parks located in Colorado have had impacts as high as $7‐9 million dollars per year. Table 2

illustrates some typical economic impacts of these parks:

Table 2: Economic Impacts of River Parks (per year in US Dollars) (Multiple sources).

The impacts of these parks are diverse and are based on regular usage of the River Park, as well as

instructional programs, competitions, festivals, and other recreational events. Freestyle events like those

that occur weekly in Colorado during spring can bring millions of dollars into the local economy on a single

weekend alone such as the GoPro games in Vail, CO which reported an economic impact of $4.7 million

dollars in 2013 (Wong, 2014). In addition to creating economic impacts, these events also help to market

a particular community as an outdoor town and whitewater destination.

River Location User Days Additional SpendingTotal Impacts

(Millions)

Clear Creek Golden, CO 13,000‐14,000 $910,000‐$1.1 Million $1.3‐2.2 Million

Blue River Breckenridge, CO 1,200‐2,300 $220,000‐$460,000 $0.4‐$1.1 Million

Gore Creek Vail, CO 1000‐2,300 $3.5 Million $3.5‐$4 Million

Sacandaga River Saratoga/Warren County, NY 17,600‐25,400 $1.8‐$2.8 Million $2.3‐$3.7 Million

Cuyahoga River Kent, OH 10,000‐40,000 $200,000‐$800,000 $0.5‐$1.7 Million

Yampa River Steamboat Springs, CO 75,700 $4.9 Million $7.2 Million

Economic Impacts of River Parks


Land Ownership

Figure 7. Land ownership adjacent to the proposed river park (City of Danville, 2016).

All proposed changes to the channel and developments of the overbank area for access and ease of

spectating would require the written approval of both landowners. Figure 7, above, shows the land

ownership near the site and details are listed below in Table 3.

Table 3: Land ownership adjacent to the Dan Rive project site (Buffalo County Assessors, 2015)

Parcel ID Owner Mailing Address

21344, 23568, 23264, 22028, 23110

WHITE MILL DEV LLC 9855 WARREN H ABERNATHY SPARTANBURG, SC 29301

5151, 5152 YMCA 215 RIVERSIDE DR, DANVILLE, VA

1110 River Partnership LLC 135 HOLBROOK AVE, DANVILLE, VA

Conceptual Design

The proposed project is tasked with providing whitewater recreation to users of varying abilities. The

proposed project is an attempt to preserve the existing dam while mitigating the risks to in‐stream

navigation and providing an attraction for the City of Danville. The park’s design is tasked with meshing

with the proposed concepts for the proposed Danville Waterfront Park.

S2o evaluated three potential types of Whitewater Park at this site. These types included:


1. River‐wide Drop Structure: A drop structure that crosses the entire river and provides three

separate chutes that will form waves.

2. Bypass Channel: A bypass channel located along the west bank of the river and separated from

the main flow by a berm. This channel would extend from the historic dam downstream most

of the way to the Main Street Bridge.

3. Canal: An out‐of‐river canal that extends from the White River Mill Canal to the proposed

Waterfront Park, discharging back into the river just upstream of the Main Street Bridge. All of

these concepts were sketched onto a site map to contrast layout and utility below:

Figure 8. Three design options were considered for the Danville Whitewater Park. Option 1 is Riverwide, Option 2 is the Bypass Channel, and Option 3 is the Whitewater Canal..

The River‐wide Drop Structure is the most typical type of whitewater park in the United States. These

types of drop structures are known for creating attractive surfing features that are easily navigable to

inexperienced river traffic at reasonable flows. However, this design concept in a river as wide as the

Dan has some design issues. The structure would draw people away from the Waterfront Park towards

the center of the river. The design would also serve to attract users to attempt to navigate the historic

dam, leaving them vulnerable to the risks associated with this structure.

The Bypass channel/Berm solution addresses some of these issues. This concept would utilize a portion

of the total flow and place it in a controlled channel directly along the west bank of the river. The

headgate to this channel could be configured to improve fish passage while also controlling the amount

of flow and degree of whitewater in the channel. This type of channel would likely not create a

significant national attraction, but would draw many local users who could safely navigate the channel in

a variety of craft.

The canal option would have the most impact to the City of Danville. This option utilizes the drop from

not just the historic dam, but also from the next dam located upstream. The combined drop is more

than 15’. This type of canal would mimic the drop and flow in the US National Whitewater Center

(USNWC) providing world class whitewater that can be used by many types of users. This site would be

significantly cheaper to operate than the USNWC, which requires extensive pumping.


For these reasons the second two options were selected for further refinement. The following section

shows the two proposed design concepts along with typical images that show how this type of

whitewater park can look and function:

The Bypass Channel

Figure 9: The proposed bypass channel would utilize the existing bed, but separate the channel from the main flow by means of a long berm.

Figure 9, above, shows the proposed layout for the bypass channel. This concept would require tapping

the historic dam with a headgate structure that would regulate flow into the bypass channel. This type of

headgate would be lowered to a submerged state and flows would flow over the headgate forming a wave

as they enter the channel. At all reasonable flows this headgate would control how much flow came into

the proposed canal and could be articulated to allow less flow for beginner/intermediate usage or more

flow for intermediate/expert usage.

The berm would be formed of natural rock and would be irregular with areas for planting riparian

vegetation as well as hard armoring where appropriate.

The channel would create waves, eddies, chutes and other whitewater features conducive to floating,

recreational paddling, river surfing, and competitions. There would be two additional feature waves in

addition to the headgate. Each of these would be surfable at varying flows and would create the signature

attractions within the channels. All of the features would be navigable by inner‐tube at lower flows but


would require more advanced paddling skills for higher flows. The figures below show how this channel

could look and function:

Figure 10. A head gate and berm would separate the channel from the main flow over the dam.

Figure 11. The channel would create waves, chutes, eddies, and other features that are attractive to paddlers of all abilities.


Figure 12. River‐wide structures can be built in parallel with the bypass channel, allowing for many types of in‐stream recreation.

The Canal

Figure 13: The canal utilizes an existing headgate and canal located adjacent to the Former White Mill to provide flow for a whitewater channel that flows through the Proposed Waterfront Park.


The whitewater canal is a unique and innovative way to showcase Danville’s manufacturing history. The

historic mill race can be retasked as a tourist attraction that would draw visitors from throughout the

region. This type of park, which is similar in nature to the USNWC, mimics a project in South Bend, Indiana,

wherein the East Race was transformed into a whitewater channel that features rafting and kayaking and

has hosted national and international competitions.

The canal would revitalize the entrance to the Former White Mill which is now being offered for sale and

redevelopment. Active, but calm and slow, flow along this canal would allow for canoeing, punting, or

stand‐up paddleboarding in a controlled environment adding energy and activity to this gateway corridor

to the mill.

The whitewater would begin at the south side of the building and would extend along a 1022 foot reach

before discharging into the Dan River. This channel would have the same approximate slope and shape

as the USNWC allowing for reconfigurable whitewater that could be configured to be either difficult, for

expert competitions, or simple, for day‐to‐day usage. A channel of this type would have a significant

advantage over pumped facilities due to the low operating costs. This design option would draw

paddlers from throughout the nation and region and would be a significant, and potentially very

profitable, attraction within the City of Danville.

The figures below show how this channel could look and function:

Figure 14. The Eiskanal in Augsburg, Germany connects industrial canals back to the Lech River and played host to the 1972 Olympic Games.


Figure 15. The East Race transformed a former industrial canal into a rafting and kayaking channel in the heart of downtown South Bend, IN.

Figure 16. The USNWC in Charlotte, NC attracts almost a million people a year to raft and play in these whitewater canals.


Opinion of Probable Costs

The conceptual level cost estimates for the Bypass Channel concept are shown below:

Table 4: Cost Estimate for the Bypass Channel configuration.

Description Quantity Unit Unit Cost Item Total Cost

Site Setup

Install & Maintain Best Management Practices 1.0 LS 5,000.00$ 5,000.00$

Circulation Paths & Access Steps

Trail Excavation 1333.3 yd^3 33.00$ 44,000.00$

Retaining Walls 0.0 yd^3 250.00$ -$

Steps 101.7 yd^3 250.00$ 25,416.67$

In Stream River Structures

Operate & Maintain Water Control 1.0 LS 55,000.00$ 55,000.00$

Install Equipment Access Ramps & Roads 4.0 EA 1,500.00$ 6,000.00$

Reclaim Equipment Access Ramps, Roads, & Staging Areas 4.0 EA 2,500.00$ 10,000.00$

Headgate Works 1.0 EA 250,000.00$ 250,000.00$

Obermeyer Adjustable Gates 1.0 EA 120,000.00$ 120,000.00$

Furnish & Install Boulder (Avg 36" B Axis) 6392.2 Tons 85.00$ 543,334.92$

Excavate & Grade Native Alluvium 1279.3 CY 22.00$ 28,144.05$

Furnish & Install Bedding Material 8715.6 Tons 30.00$ 261,467.57$

Furnish & Install Mirafi 180n Filter Fabric 3260.7 SY 8.00$ 26,085.56$

Furnish & Install Concrete Grout, Including Rebar, & Marine Epoxy 674.2 CY 272.00$ 183,375.14$

Furnish & Install by Hand Washed Rock Veneer 464.8 Tons 120.00$ 55,781.35$

Unclassified Hauloff 1279.3 CY 20.00$ 25,585.50$

-$

Additional Included Items

Additional Excavator Time as directed by S2o 80 HR 220.00$ 17,600.00$

PROJECT SUBTOTAL 1,656,790.75$

Contingency (20%) 331,358.15$

CONSTRUCTION SUBTOTAL 1,988,148.90$

Bathymetric/Topographic Survey 19,881.49$

Engineering Design 139,170.42$

Hydraulic Modeling 19,881.49$

Permitting 404, 401 39,762.98$

Permitting Floodplain 39,762.98$

Construction Bonding/Ins 59,644.47$

Mob and Demob 59,644.47$

Construction Stakeout 9,940.74$

Construction Monitoring 159,051.91$

TOTAL PROJECT COST OPINION 2,534,889.8$

Project: Danville Whitewater Park

Issue Date: 2/28/2017

Developed By: MR, SS

Danville In-Stream Bypass Channel


The conceptual level cost estimates for the Whitewater Canal concept are shown below:

Table 5: Cost Estimate for the Canal Configuration

Description Quantity Unit Unit Cost Item Total Cost

Site Setup

Install & Maintain Best Management Practices 1.0 LS 5,000.00$ 5,000.00$

Water Source

Restore headgate 1.0 LS $150,000 150,000.00$

Clean and restore feeder canal (assumes only excavation) 3238.8 yd^3 20.00$ 64,775.93$

Circulation Paths & Access Steps

Trail Excavation 2201.4 yd^3 33.00$ 72,645.83$

Retaining Walls 875.0 yd^3 250.00$ 218,750.00$

Steps 171 0 250.00$ 42,638.89$

Trail Concrete 114 0 250.00$ 28,472.22$

Canal River Structures

Excavate & Grade Native Alluvium 10523.3 yd^3 22.00$ 231,513.33$

Channel Concrete 1275.6 yd^3 250.00$ 318,888.89$

Waterproof Membrane 45920.0 ft^2 3.65$ 167,608.00$

Furnish and Install Rapidblocs 336124.0 EA 1.00$ 336,124.00$

Furnish and Install Unistrut 20440.0 LF 4.88$ 99,707.32$

Bridges

Furnish and Install Bridges 2.0 ea $60,000 120,000.00$

PROJECT SUBTOTAL 1,856,124.41$

Contingency (15%) 278,418.66$

CONSTRUCTION SUBTOTAL 2,134,543.07$

Bathymetric/Topographic Survey 21,345.43$

Engineering Design 149,418.01$

Hydraulic Modeling 21,345.43$

Permitting 404, 401 21,345.43$

Permitting Floodplain 21,345.43$

Construction Bonding/Ins 64,036.29$

Mob and Demob 64,036.29$

Construction Stakeout 10,672.72$

Construction Monitoring 170,763.45$

TOTAL PROJECT COST OPINION 2,678,851.6$

Project: Danville Canal Concept

Issue Date: 3/2/2017

Developed By: SS, MR

Danville Canal: Estimated Design and Construction Costs


Permitting

River parks, typically require Federal, State, and Local permits prior to the initiation of construction

activities. Obtaining these approvals may require a number of tasks, including but not limited to:

Detailed site survey;

Wetland delineations;

Historic structures and/or culturally significant resources surveys;

Threatened and endangered species surveys;

Establishment of a Proposed Conditions flood model; and

Issuance of design drawings stamped by a licensed professional engineer.

Federal and State Permitting

River Parks within the United States require, at minimum, a 404/401 permit. This joint permit application

involves a thorough review process, which includes an assessment of all impacts of the proposed park to

the environment including an alternatives analysis demonstrating that the selected project is the least

environmentally damaging and most practicable alternative. During this review, coordination with both

the Virginia Department of Water Quality and the US Fish and Wildlife Service (USFWS) may be required.

The Virginia Water Protection Permit Program serves as Virginia’s 401 certification program for federal

Section 404 permits issued under the authority of the Clean Water Act. The following Federal and State

permits are anticipated for this project:

U.S. Army Corps of Engineers (USACE) –Section 404 Individual Permit; and

Virginia Department of Environmental Quality ‐ Section 401 Water Quality Permit.

City of Danville

Depending on the location or locations of the selected project sites, various Danville City development

permits may be required including land use review and/or local building permits. The following

development permits are anticipated. Building permits and other approvals may also be required.

Virginia Storm Water Management (VSMP) Permit

Land Disturbance Permit

Floodplain Development Permit (possibly with the County)

Floodplain Development Permit (City or County)

Whitewater Parks are constructed to meet all Federal, State, and Local codes and are designed using flood

modeling software approved by the US Army Corps of Engineers in order to receive floodplain

development permits. These river parks can typically be designed to a “no‐rise” condition, which ensures

no impact during the 1% chance annual flood (100 year flood) to neighboring properties or changes to

existing flood hazard zoning and associated flood insurance requirements. This condition requires that

proposed changes within 100 year floodplain create no net increase in modeled water surface elevations


during the 100 year base flood. Base Flood Elevations (BFE) are used to define effective water surface

elevations at sites where detailed flood studies have been performed.

A requirement of the National Flood Insurance Program is that a proposed project can create no‐net‐

negative‐impact to insurable structures. This requirement is particularly robust in the regulatory

floodway.

The configuration of this site substantiates the need for a project designed to meet a no‐rise requirement.

The challenge in this instance will be to find a design that focuses flows and energy at lower flows (by

consolidating drop at average flows) but that does not cause a rise at higher flows.

The Design and Construction Process

This study has evaluated the site and suggested possible design solutions that satisfy specific project site

constraints and requirements and that would provide for a river based recreational attraction. This is not,

however, a completed design that is ready to be constructed. Additional project phases including

preliminary design, detailed design and final construction documentation are necessary before

construction at the preferred alternative project sites can begin.

Design

Figure 17: River Parks are designed for many differing kinds of users.

River parks typically require several stages of design. The following outlines S2o’s typical process from

design through construction:

a) Feasibility/Conceptual Design—this is the first must‐do part of a project. This phase is tasked

with determining whether a particular project is possible and, if so, how it could look and function

and what the approximate costs of the project would be. If done right this part of the project is

very powerful as it provides the client with the materials necessary to pursue funding and grants

and documentation useful for preliminary public process and stakeholder coordination.

Deliverables include a feasibility report outlining project site opportunities and constraints, tasks


for completion, and permit requirements along with conceptual design drawings and budgetary

cost estimates.

b) Preliminary Design—this phase gets to the heart of the design elements of project. If the

Feasibility phase is about identifying what needs to be done to complete a project, Preliminary

Design is about doing them. It is a phase tasked with completing the necessary actions required

to finalize the design functionality and layout and to gather and process the data necessary to

undertake detailed design. Preliminary Design often includes all of the tasks related to preparing

for permitting, surveying, creating baseline models, meeting with stakeholders and agencies to

define constraints and objectives, and completing design documents to the permitting level.

c) Permitting—permitting is a process that permeates most of the design phases. It is typical to

work with regulatory authorities during the preliminary design phase to establish criteria and

priorities for the project. Permit applications are typically submitted following the completion of

Preliminary Design. Some permits, as outlined below, have lengthy review times for specialty

projects such as river parks.

d) Detailed Design—the detailed design is about getting to the nuts‐and‐bolts of the project. Now

that the project has been defined and adapted to the constraints and objectives laid out in

Preliminary design the project is ready for detailed calculations and modeling. Often the level of

computations and modeling is defined by the nature of the project. In some cases, such as the

Holme‐Pierrepont River Park, the project can be accomplished with 1‐dimensional modeling. In

other cases, such as the Calgary River Park, detailed physical models were undertaken.

e) Construction Documentation—this is the “after‐design” phase. Documents are created that help

define the project for the contractor including all sections, details, specifications and bid items.

Often the River park designer will work with the client or the community to step through these

processes.

f) Project Bidding and Construction—the project is put to bid by the project owner and a contractor

is selected and contracted.

g) Construction Oversight and Inspection—in this phase the contractor and the design team work

together to build the project to our exacting specifications. Often we have representatives in the

field virtually full‐time to ensure an accurate build that is aesthetically beautifully and highly

functional!

h) Course Commissioning—the final phase and the one where we finally get to get wet! Paddling

experts get in the water and test the project, often tuning wave characteristics and project

features until the project is fully functional and meets design objectives.

The process of design is informed by the input from the project owner, local stakeholders, and regulatory

agencies and is typically based on a standard of care that is evolving for this new industry.

Construction

Once detailed construction drawings, specifications, and bid information have been developed and the

permits have been obtained, construction of the project may begin. The anticipated construction timeline

for each of the concept plans described above ranges from three to six months, depending on the number

and size of the drop structures proposed, along with the overall complexity of the total project area


improvements. In‐channel construction activities typically occur when the flows are at seasonal lows and

when there is the least impact to aquatic species.


Appendix A: Glossary

These terms are often used in the white water parks business. Let us know if you are left wondering about

a term or phrase—we’ll add it to the list!

2‐Dimensional Flow Models: Flow models such as River 2d show the nature and distribution of flows.

Flow 2d models are often useful for establishing fish passage by adjusting the design to meet flow criteria

established with permitting authorities.

3‐Dimensional Flow Models: Flow models such as Fluent or Flow 3d that use computational fluid

dynamics to compute virtually every characteristic of the flow including vortices, turbulence, water

surface character, and more. These models are often less informative and more expensive than creating

an actual physical model.

Business and Market Analysis: A study that establishes what the market potential for a whitewater park

is in a given community including total expected visitorship and the character and demographics of these

visitors. We also use research data to establish price point and complementary amenities. Based on this

information we create a business and operations model for the client. Our models are very robust and

have, without comment, been reviewed by independent as well as state and banking reviewers in

preparation for grant and loan funding. Beware of freebie and cheap “general purpose” business models.

These are the only white water park business models that provide operators and financiers the

information that they need, for their project, to make it happen.

Class I‐VI: Whitewater rapids can be classified according to difficulty and risk. A generally accepted

classification system typically uses roman numerals between I and VI with I being the easiest to navigate

and appropriate for beginners with obvious lines and very little power and class VI being the most difficult

with steep and powerful lines that are difficult to attain and maintain even for the best expert boaters.

Dangerous “Keeper” Hydraulic: Hydraulic jumps vary in power and character. In general the gamut of

hydraulic jump types varies from glassy green wave to a hydraulic jump that features dangerous

recirculating currents that swimmers have difficulty existing. The designers challenge in whitewater park

design is to create a whitewater feature that has sufficient power to be a play feature, but not so much

power that it creates a hazard to beginner boaters.

Economic Impact Study: A study completed in cooperation with a PhD in economics. We study the

economics of the region surrounding the park and establish, based on published data (or surveyed data if

published data does not exist) what the economic impact of a whitewater park will be to a host community

in terms of total dollars, increased tax revenue, increased average incomes, increased jobs, and other

pertinent economic metrics.

EPDUK: S2o’s design partner in Great Britain. S2o and EPDUK partnered together on several projects

including the London Olympic Park Project.

Floodplain Analysis: A process that undertaken to understand the effect of a whitewater park on a

floodplain at a particular project site. Often the floodplain analysis is conducted hand‐in‐hand with the

project design to minimize or eliminate flooding impacts.


Freestyle Feature: A surf or play feature of sufficient size and power to be used for Freestyle, or trick

kayaking, competitions.

Freestyle kayaking: A type of whitewater competition in which paddlers surf in a wave or hydraulic and

perform tricks over a set time period. The paddlers are scored according to style, difficulty, and number

and variety of tricks. Large events such as the GoPro (formerly Teva) Mountain Games, which are held in

the Nick Turner (now of S2o) designed pneumatically adjustable play feature can have an economic impact

of $3.5 million dollars in a single weekend event!

HEC‐RAS Model: a one dimensional flow model developed by the Army Corps of Engineers to predict

flood elevations in rivers. This software has limited applications to Whitewater Design—particularly

within floodplains.

Kayak Park: A whitewater park designed specifically for kayaking. Many of the freestyle whitewater parks

are custom designed to create waves and play‐holes specifically for kayaking

Physical Model: A Froude scaled model that is hydraulically scaled (using the Froude number relationship)

to mimic the behavior of a full‐sized river. If done properly this model can accurately predict wave size,

height, and shape as well as depths, velocities, and other pertinent course features.

Play Features: Similar to Surfing Features. Surfing features in whitewater parks are waves or hydraulic

jumps which are conducive to surfing a kayak, stand‐up‐paddleboard (SUP) or surf board. These waves

are called standing waves and remain stationary in the current (in comparison to waves in the ocean which

transit a body of water and break on the beach).

Run‐Of‐The‐River Type Features: Whitewater Park features which are a challenge or that augment the

experience of running the river. These features contrast with Freestyle and Play features in that they

provide a navigational challenge to varying levels of boater.

Slalom kayaking: A type of whitewater competition in which kayakers are timed going through a set

course of slalom gates (poles hung from wires above the river/channel). Paddlers are timed and scored

with the winner posting the fastest time. Large events, such as the 2008 Olympic Team Trials can have as

many as 30,000 spectators in a single weekend and can have millions of dollars in economic impact to a

hosting town or city.

Slalom Racing/Slalom Features: Whitewater Slalom Racing is a timed event wherein kayakers race

through a set of 18‐25 slalom gates hung in a whitewater rapid. Athletes are scored based on total running

time plus assessed penalties for touching or missing the gates. Slalom Features are features that are

conducive to setting challenging slalom courses.

Surfing Features: Similar to Play Features. Surfing features in whitewater parks are waves or hydraulic

jumps which are conducive to surfing a kayak, stand‐up‐paddleboard (SUP) or surf board. These waves

are called standing waves and remain stationary in the current (in comparison to waves in the ocean which

transit a body of water and break on the beach).

Swiftwater Rescue Park: a park designed specifically to help train rescue authorities in swift water rescue.

These parks can hold cars, trees, and platforms in the main flow and can be turned off in an instant if a

rescue or scenario becomes dangerous.


Whitewater Park Design: The planning, design, market and business analysis, and creation of

construction documents for a white water park.

Whitewater Raft: a watercraft that is inflatable that is typically designed to carry paddlers through a

whitewater rafting. Rafters can be commercial rafters as a part of a for‐profit business, or private rafters,

who own or acquire their own inflatable watercraft.

Width, Depth, And Aspect Ratio When Referring to Whitewater Features: Constructed whitewater

features—in particular freestyle features—typically span the river or channel in which they were built.

These features, in order to meet permit and FEMA requirements need to match existing river morphology

in the reach. As a rule the existing bed therefore defines the width, depth, and aspect ratio of the existing

river bed and the designer often checks, by inspection, that the selected location is appropriate for

improvements given the existing aspect ratio of the river.


Appendix B – Conceptual Designs

11282016 Site Visit and Conceptual Design Study issue

Documents

Transcript of 11282016 Site Visit and Conceptual Design Study issue